New oxyacetic ether derivatives of ortho-thymotic esters

ABSTRACT

New derivatives of the formula:   in which R represents a lower alkyl radical having 1-4 carbon atoms; n is an integer from 1 to 4; R2 is hydrogen or a lower alkyl radical, the various R2&#39;&#39;s not being necessarily identical when n is higher than 1; R3 and R4, which may be the same or different, are hydrogen or a lower alkyl radical or, together with the nitrogen atom to which they are attached, form a heterocyclic ring which may contain another heteroatom and their pharmaceutically acceptable acid addition salts. They are useful, in particular, as therapeutic compositions having cranial and peripheral vasodilatator, coronary dilatator, local anesthetic and anti-tussive properties.

United States Patent 1 Castaigne l l NEW OXYACETIC ETHER DERIVATIVES OF ORTHO-THYMOTIC ESTERS [75] Inventor: Albert Rene Castaigne, Toulouse.

France [73} Assignee: Centre dEtudes pour llndustrie Pharmaceutique. Toulouse France [22] Filed: July 6, I973 [21] Appl. No.: 377,030

[30] Foreign Application Priority Data July 20, V972 France i a i a a a i a 7226K) [52] US. Cl 260/472; 260/4272 B; 260/29382; 260/473 lG; 424/248; 424/267; 424/309 [5i] Int. Cl. C07C 101/42 [58] Field of Search 260/471 473 I0 [56] References Cited OTHER PUBLICATIONS Finar; l. L., Organic Chemistry (Vol. l)l963. pub by Richard Clay & Co.-London (QDZS l F6), pp. W6,

Primary E.run1im'rRobert Gcrstl Assistant IiruminerL. A. Thaxton Almrney. Agent or FirmYoung & Thompson 145] Aug. 26, 1975 I57] ABSTRACT New derivatives of the formula:

in which R represents a lower alkyl radical having l4 carbon atoms; n is an integer from 1 to 4; R is hydrogen or a lower alkyl radical, the various R 's not being necessarily identical when n is higher than I; R and R, which may be the same or different, are hydrogen or a lower alkyl radical or together with the nitrogen atom to which they are attached form a heterocyclic ring which may contain another heteroatom and their pharmaccutically acceptable acid addition salts. They are useful, in particular as therapeutic compositions having cranial and peripheral vasodilatator. coronary dilatator. local anesthetic and anti-tussive properties,

6 Claims, No Drawings NEW OXYACETIC ETHER DERIVATIVES OF ORTHO-THYMOTIC ESTERS This invention relates to new ortho-thymotic acid derivatives, to a process for their preparation and to their applications. particularly in human and veterinary medicine.

The new compounds of this invention are those having the general formula:

in which R represents a lower alkyl radical having 1-4 carbon atoms; n is an integer from 1 to 4; R considered individually in each radical (CHR is hydrogen or 7 a lower alkyl radical having 1-6 carbon atoms; R and R, which may be the same or different, are hydrogen or a lower alkyl radical having 1-6 carbon atoms or, together with the nitrogen atom to which they are attached. form a heterocyclic ring optionally containing another heteroatom and their pharmaceutically acceptable acid addition salts.

It is apparent from the above definition that the various symbols R are not necessarily identical when n is higher than 1.

Among the acid addition salts, may be mentioned the salts formed with inorganic acids (hydrochloric, sulfuric, phosphoric acids) or organic acids (oxalic, succinic, citric acids).

The invention includes also within its scope a process for the preparation of said derivatives, comprising reacting ortho-thymotic acid having the formula:

with an esterifying agent of the formula A( R) in which R has the above defined meaning, A is an anion and a is the valence of said anion, to give the derivative of the formula (11) H CH3 COOR 0421 -4203 (111) /CH 3 c \31 in which R is a lower alkoxy radical, hydrolyzing group COR to a carboxyl group, estcrifying same with an aminoalcohol of the formula in which R, R, R and n have the above defined meanings and, if desired. salifying resulting derivative of the formula (I).

Said esterification is advantageously effected by means of an alkyl sulfate. It is preferably conducted within boiling acetone in the presence of sodium acid carbonate.

Treatment of derivative (ll) with the lower alkyl halogenoacetate is effected by heating the reagents within a solvent, such as dimethylformamide, in the presence of a base, such as potassium carbonate, taking up the hydrohalic acid released.

To hydrolyse selectively the COR group of resulting compound (111). the reaction is conducted in alkaline medium at moderate temperature.

To esterify the resulting acid (compound (III), R OH) with the aminoalcohol, it is convenient to first convert it to an acid chloride (compound (11] R =Cl) with thionyl chloride and to react said acid chloride with the aminoalcohol under usual esterification condi tions.

All compounds (Ill). whether R is a lower alkoxy group, a hydroxy group or chlorine, are new compounds also encompassed within the scope of this invention.

The following non limiting examples are given to il lustrate the preparation of compounds of this invention.

Examples A and B relate to the preparation of esters (11) used as raw materials in subsequent examples.

EXAMPLE A Synthesis of methyl ortho-thymotatc To a two-necked flask provided with a mehchanical stirrer and with an ascending cooler provided overhead with a calcium chloride tube are added 48.55 g (0.25 mole) ortho-thymotic acid, 35.28 g (0.28 mole) methyl sulfate. 25.2 g (0.30 mole) hydrogen sodium carbonate and 200 ml anhydrous acetone.

The mixture is boiled during 15 hours, with eontinu ous stirring.

After cooling. the solution is filtered and the filter is EXAMPLE B Synthesis of ethyl ortho-thymotate This ester is obtained as its methyl homolog (Examle A) by mixing at first 48.55 g (0.25 mole) orthoiymotic acid. 45.17 g (0.28 mole) ethyl sulfate and 5.2 g sodium acid carbonate in 200 m1 anhydrous ace- The fraction distilling at 8824 89C under 0.5 mm

1g is collected (Yield: 78%

EXAMPLE I a. Synthesis of ethyl (6-isopropyl-2- 1ethoxycarbonyl-3-methyl)-phenoxyacetate To a 1 liter threemecked flask provided with a mehanical stirrer and with a cooler provided overhead vith a calcium chloride trap are added 100 g (0.48 nole) methyl ortho-thymotate, 80.16 g (0.48 mole) thyl bromoacetate. 128.48 g (0.96 mole) anhydrous iotassium carbonate and 200 ml anhydrous dimethyl ormamide.

The mixture is heated 18 hours at 55C. After coolng, the solution is filtered and the precipitate is washed vith acetone. The filtrate to which the washing acetone 5 added is evaporated and the residue is dissolved in :ther.

The ether phase is washed with water, dried over aniydrous sodium sulfate, filtered, evaporated and disilled in vacuo. to give 124.55 g (Yield: 88%) of a dcivative having a boiling point (under 0.1 mm Hg) of 40C.

b. Synthesis of (6-isopropyl-2-methoxycarbonyl-3- nethyl )-phcnoxyacetic acid.

To a 1 liter flask are added 80 g (0.272 mole) ethyl 6-isopropyl-Z-methoxyearbonyl-3-methyl Jhenoxyacetatc. 285 ml N NaOH and 180 ml ethanol. l'he resulting pink solution is left at room temperature luring 48 hours after which the ethanol is evaporated n vacuo. The remaining aqueous phase is extracted vith ether. it is then made acidic and again extracted with ether.

The ether extracts are dried over anhydrous sodium iulfatc and are then filtered and evaporated. to give 72.58 g (Yield: 100%) of an oil which crystallizes very 'apidly and has a melting point (Koefler block) of )092C.

c. Synthesis of (6-isopropyl-2-methoxyearbonyl-3- nethylkphenoxyacetic acid chloride.

To a 100 ml flask are added 6 g (0.0266 mole) (6- sopropyl-2-methoxycarbonyl-3-methyl )henoxyacetic acid. 12 ml thionyl chloride and 2 drops .limethylformamide. The mixture is refluxed during me half hour and is then evaporated in vacuo. The re- ;ulting acid chloride is used directly in the following step.

d. Synthesis of N-dimethylaminoethyl (6-isopropyl-2- methoxycarbonyl-3-methyl )-phenoxyacetatc tive No. 1)

in a three-necked flask of 250 ml capacity. provided with a magnetic stirrer. a cooler provided overhead with a calcium chloride trap, and a dropping funnel are mixed 2.37 g (0.0266 mole) dimethylaminoethanol and ml chloroform and the acid chloride obtained above. dissolved in 35 ml anhydrous ether, is then added dropwise thereto. When the addition is completc. the reaction mixture is stirred 15 minutes at room temperature, ml of 5% hydrochloric acid are added thereto and the mixture is again stirred vigorously during 10 minutes. The aqueous phase is de' canted, made alkaline with 2N sodium hydroxide and extracted with ether.

The ether phase is dried over anhydrous sodium sulfate. filtered and evaporated in vacuo, to give 5.13 g of an oil which is directly converted to the hydrochloride. After recrystallization from ethyl acetateethano1, there are obtained crystals having a melting point (Koeflcr block) of 138l40C.

EXAMPLE 2 Synthesis of piperidinoethyl (6-isopropyl-2- methoxycarbonylB-methyl)-phenoxyacetate (Derivative No. 2)

In a three-necked flask of 500 ml capacity provided with a magnetic stirrer, a cooler provided overhead with a calcium chloride trap, and a dropping funnel are mixed 4.77 g (0.0376 mole) piperidinoethanol in 100 ml chloroform. The acid chloride (obtained as in Example 1c from 10 g (6-isopropyl-2-methoxy-earbonyl- 3-methyl)phenoxyacetic acid) dissolved in 50 ml ether is then added thereto dropwise. When addition of the acid chloride is complete, the reaction mixture is stirred 15 minutes at room temperature after which 100 ml 5% hydrochloric acid are added thereto. and the reaction mixture is stirred vigorously during 10 minutes. The aqueous phase is decanted. made basic with 2N sodium hydroxide and extracted with ether. The ether phases are dried over anhydrous sodium sulfate, filtered and evaporated in vacuo. to give 12.22 g of an oil which is directly converted to the hydrochloride. Recrystallization from ethyl acetate-ethanol gives 9.17 g of crystals having a melting point (Koefler block) of 140C.

Other derivatives of the formula (I) were obtained by synthesis. The characteristics of some of said derivatives are given below. for illustrative purposes: N-dimethylaminoethyl (fi-isopropyl-Z-cthoxycarbonyl- 3-methy1)-phenoxyacetate whose oxalate. recrystallized from ethyl acetate-ethanol has a melting point of C (Derivative No. 3].

N-diethylaminocthyl (6-isopropy1-2-methoxycarbonyl- 3-methyl)phenoxyacetate whose oxalate. recrystallized from ethyl acetate. has a melting point of ll0112C (Derivative No. 4).

Morpholinoethyl (6 isopropyl2-mcthoxycarbony1-3- methylJ-phenoxyacctate whose oxalate, recrystallized from ethyl acetatcethanol has a melting point of l40-l42C (Derivative No. 5).

N-dimethylaminoisopropyl ((i-isopropyl-flmethoxycarbonyLZanethyl)-phcnoxyacetate whose hydrochloride. recrystalliyed from ethyl acetateethanol. has a melting point of 12712)C (Derivative No. 6).

(Deriva- N-dimethylaminopropyl (6-isopropyl-2- methoxycarbonyl-3-methylJ-phcnoxyacetate whose hydrochloride. recrystallized from ethyl acetateethanol. has a melting point of l l8l20C (Derivative No. 7].

The results of toxicological and pharmacological tests reported below demonstrate the activities of the derivatives of this invention, particularly their cranial and peripheral vasodilatator, coronary dilatator, local anesthetic and anti-tussive activities.

Thus, the invention includes also within its scope a therapeutic composition having in particular cranial and peripheral vasodilatator, coronary dilatator, local anesthetic and anti-tussive actions, comprising, as active ingredient, a derivative of the formula (I) or a pharmaceutically acceptable salt thereof and a therapeutically administrable carrier.

I. TOXICOLOGICAL INVESTIGATION The low toxicity and the good tolerance of the derivatives of this invention are apparent from said investi' gation.

For indicative purposes the LD 50/24 hrs, determined according to the method of Miller and Tainter in mice, for the intravenous route per kg of body weight is 135 mg for derivative 1, 50 mg for derivative 2, 130 mg for derivative 3. 82 mg for derivative 4, 145 mg for derivative 5, 42 mg for derivative 6 and 90 mg for derivative 7.

II. PHARMACOLOGICAL INVESTIGATION a. cranial and peripheral vasodilatator action On intravenous injection at a dosage of IO mg/kg of body weight. the derivatives of this invention produce a marked cranial and peripheral vasodilatation. Said action is evidenced by the rheographic study: this study shows an increase of the amplitude of the rheographic recording and. therefore, an increase of the blood rate of flow due to a vasodilatation in the area under consid eration.

b. coronary dilatator action This experimentation, effected with the normal iso- Iated heart of rabbit according to Langendorffs technique (GAZET du CHATELIER G. and STRASKY E.. Ann. Pharm. Fr., [956. 14, ll. 67768S) shows that addition of the derivatives of this invention to the nutri ent perfusion liquid produces an increase of 40-60% of the coronary rate of flow and. thus. a marked vasodilatation at the level of the coronary arteries.

c. local anesthetic action This action was investigated by means of the local surface anesthesia method (disappearance of the oculo-palpcbral reflex in rabbit. according to Rgnier, These Med, Paris, 1929; Roland, These Pharm.. Toulouse, l957 Hazard and Coll. Masson et Cie., Ed. I963. p. 5859) and by means of the local infiltration anesthesia method of BULBRING & WAJDA, J. Pharmacol. Exptl. Therap, I945, 85. 78. 84.

This investigation shows that the derivatives of this invention provide anesthesia percentages within the range from 50 to 607:.

d. anti-tussive action (Method of Salle-Brunnaud, Arch. Int. Pharmacodyn. l-Z. l-l2, I960)v The guineapigs. placed in a sealed enclosure, are submitted. prior and after treatment with the derivatives of this invention. to the action of a coughproducing agent (aerosol containing one third ammonia) during one minute and then receive pulsed air during 2 minutes.

The coughing motions are recorded on a cylinder by means ofa Marey cell. The anti-tussive activity of the test materials is evaluated as a function of the decrease of the coughing motions in the animals of the treated lot with respect to the reference lot. Said activity is, on the average, 30 minutes after treatment and 5871 minutes after treatment.

The cranial and peripheral vasodilatator, coronary dilatator, local anesthetic and anti-tussive activities of the derivatives of this invention, and also their low toxicity and good tolerance are apparent from the results of said investigations.

The therapeutic composition of this invention is advantageously formulated for oral administration as tablets, coated tablets, capsules, syrups and drops. It may also be formulated as injectable solutions or as suppositories.

Each unit does may advantageously contain 20-250 mg active ingredient, the daily dosage regimen varying within a wide range from 20 mg to 2.000 mg.

Non limiting examples of pharmaceutical formulations of the composition of this invention are given below.

EXAMPLE 3 Tablets Derivative No. 3 0. I00 g Lactose 0,0l5 g Starch 0.0l0 g Magnesium stearate 0.005 g Polyvinyl pyrrolidone 0.010 g Aluminum tartrazine lacquer traces EXAMPLE 4 Coated Tablets (Derivative No. l 0.02m g Lactose 0.010 g Core Starch 0.010 g (Talc 0.005 g (Polyvinyl pyrrolidone 0.0l0 g Magnesium stearate 0.005 g Sugar 0.0l5 g (White gelatin 0.010 g Coating (Tricalcium phosphate 0.003 g (Gum arabic 0.005 g l artrazine traces (White wax 0.005 g ((arnauha wax 0.002 g EXAMPLE 5 Capsules Derivative No. 2 0.075 g Talc (1.005 g Magnesium stearate 0.005 g EXAMPLE 6 Drops Derivative No. 5 L5 Flavoured excipient. q.s. to make 30 ml EXAMPLE 7 Injectable solution Derivative No. 4 0.075 g isotonic solvent q.s. to make 3 ml EXAMPLE 8 Suppositories Derivative No. 7 0 I00 g Semi-synthetic glyceridcs, q.s. for l suppository The composition of this invention may be used for therapeutic purposes for its cranial and peripheral vasodilatator, coronary dilatator. local anesthetic and anti-tussive properties.

It is used as a local anesthetic in surgery, traumatology, rheumatology and oto-rhino-laryngology.

In view of its cranial. peripheral and coronary dilatator properties, it is administered in the treatment of cardiovascular conditions.

Finally, it produces rapid sedation of coughing. what ever its etiology. while being free from unpleasant side effects.

Having now described my invention what I claim as 16W and desire to secure by Letters Patent is:

l. A compound selected from the oxyacetic ether de- 'ivatives of ortho-thymotic esters of the formula:

in which R is a lower alkyl having l-4 carbon atoms; n is an integer from I to 4; R considered individually in (6-isopropyl-2- and its 

1. A COMPOUND SELECTED FROM THE OXYACETIC ETHER DERIVATIVES OF ORTHO-THYMOTIC STERS OF THE FORMULA:
 2. N-dimethylaminoethyl (6-isopropyl-2-methoxycarbonyl-3-methyl)-phenoxyacetate and its hydrochloride.
 3. N-dimethylaminoethyl (6-isopropyl-2-ethoxycarbonyl-3-methyl)-phenoxyacetate and its oxalate.
 4. N-diethylaminoethyl (6-isopropyl-2-methoxycarbonyl-3-methyl)-phenoxyacetate and its oxalate.
 5. N-dimetHylaminoisopropyl (6-isopropyl-2-methoxycarbonyl-3-methyl)-phenoxyacetate and its hydrochloride.
 6. N-dimethylaminopropyl (6-isopropyl-2-methoxycarbonyl-3-methyl)-phenoxyacetate and its hydrochloride. 